The present invention relates to a solid image capturing device, also called a solid state image capturing device, a lens unit and an image capturing apparatus adapted to be used for image capturing.
Conventionally, a solid image capturing device, e.g. a CCD (Charge Coupled Device) or an MOS (Metal Oxide Semiconductor), is used in an image capturing apparatus, such as a digital camera or a video camera.
Because these solid image capturing devices have their own characteristics, such as defective pixels or the like, it is necessary to correct defects in the pixels or to make other corrections required by the characteristics of each device in order to obtain images of good quality.
For example, Japanese Patent Publication No. 13549/1985 discloses an image capturing apparatus which includes a noise eliminating circuit for correcting defective pixels. As shown in FIG. 9, this image capturing apparatus has a CCD 3, which is adapted to conduct photoelectric transfer of an optical image of the subject 2 formed through a lens 1 to produce output signals that result from the conversion. A CCD memory device 4 serves as a noise eliminating circuit by outputting photoelectrically received defect data of the CCD 3. The defect data of the CCD 3 is optically stored in an optical mask 5. The defect data stored in the optical mask 5 is picked up by the CCD memory device 4 using light from a light source 6.
A single driving pulse generating circuit 7 drives both the CCD 3 and CCD memory device 4 by feeding them driving pulses. Outputs from the CCD 3 and the CCD memory device 4 are shown in FIG. 10. Outputs from the CCD 3 and the CCD memory device 4 are respectively processed by different circuits. Outputs from the CCD memory device 4 are processed by a circuit 8, consisting of a waveform shaping circuit and a sample holding circuit. The output of the sample holding circuit is used as gate input into a sample holding circuit 9, which processes outputs from the CCD 3 to correct defects in the CCD 3. Corresponding to defective points in the effective image field of the CCD 3, the CCD memory device 4 reads out data using the effective image field of the CCD memory device 4.
In addition to a solid image capturing device, other memories are also provided. For example, an image capturing apparatus disclosed in Japanese Utility Model Provisional Publication No. 122374/1987 includes a solid image capturing device and a ROM serving as a memory. The ROM is separate from the solid image capturing device. The ROM is dedicated to saving data characteristics to the solid image capturing device so that the data characteristics (defect data, for example) of the solid image capturing device is output from the memory and processed, by a processing circuit or the like, separately from image data, which is output from the solid image capturing device.
In addition to a solid image capturing device, an image capturing apparatus also includes a lens and a main body of the image capturing apparatus. The image capturing apparatus includes a processing circuit for processing image data output from the solid image capturing device. Because the solid image capturing device has its own characteristics, these elements are designed to be exclusively used for the particular solid image capturing device.
In order to read out properties characteristic to the solid image capturing device, the conventional design described above requires a CCD memory device 4 provided separately from an image capturing CCD 3. In other words, a circuit 8, which is separate from the circuit for processing output from the CCD 3, must be used for processing output from the CCD memory device 4. This results in an increased number of parts, a complicated configuration and an increase in size.
Because each solid image capturing device has its own characteristics, a conventional image capturing apparatus has a configuration that is different for each respective solid image capturing device. This means that different image capturing apparatuses have to be developed exclusively for each and every different kind of solid image capturing device. This presents a particularly serious problem when a new generation of solid image capturing devices appears on the market to replace older types of solid image capturing devices. The difficulty arises because it is impossible to cope with such changes immediately. The development and market entry for a new image capturing apparatus is likely to take a long period of time.